Surface exciton polariton enhanced Goos-Hänchen and Imbert-Fedorov shifts and their applications in refractive index sensing.

The spatial and angular Goos-Hänchen shifts (GHSs) and Imbert-Fedorov shifts (IFSs) are theoretically investigated in a modified Kretschmann-Raether configuration consisting of glass prism, J-aggregate cyanine dye, and air. With the excitation of surface excitation polaritons (SEPs), the spatial and angular GHSs and IFSs for the transverse magnetic polarized light are strongly enhanced around the resonant angle of SEP. A highly sensitive gas sensor based on the SEP enhanced GHS (or IFS) is proposed, which exhibits the refractive index sensitivity on the order of 10λ/RIU (or 10λ/RIU) (λ: illumination wavelength; RIU: refractive index unit) for the GHS- (or IFS-) based gas sensor, respectively.